But what stops Amazon from making these things? What's stopping them?

Almost two decades of Google market dominance with Android, and Google's simultaneous ownership of the entire ecosystem, including the browser, search engine, cloud integration and the internal app store (which is integrated so far up the OS's ass you can't do much without it). You just can't enforce a monopoly like Google does and simply claim "why wouldn't the competitors and consumers just kneecap themselves to leave??"

You'd have to get every single app developer to implement an Amazon variant of Google Play Services alongside Google's.

That's not going to happen, it's already a large problem in China.

This is a relatively simple technical problem. If Amazon implements compatible APIs, they can trivially rebuild apps to use them.

Play Services, and the Play Store. The network effect is so strong that competition becomes impossible. Nobody would buy a phone with a different AI provider because you couldn't use apps like Uber, and Uber wouldn't develop and publish to a different store and re-write their app to avoid Play Services to target a platform without any users.

What's stopping you? Reflect on that and you'll have your answer.

What's stopping me is I'm not trying to build a phone. If I were, I wouldn't be blaming Google for not making things easy enough for me.

lol and you've clearly never heard of a thought experiment

Try re-reading the second sentence.

Try engaging your brain for like 2 seconds

Holy fuck dude. Try rereading the comments in the thread that already answered your questions.

You’re not being clever like you think you are. “They could simply build something else” is … something that truly everybody knows. That’s not the point.

What is the point?

Why didn't Linux programmers just fork Windows or iOS?